﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Demo08
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("请输入菱形的边长：");
            int a = int.Parse(Console.ReadLine());
            
            for (int i = 1; i <= 2 * a -1; i++)
            {
                for (int j = 1; j <= 2 * a - a; j++)
                {
                    if (a >= i && j < a + i && j > a - i || a < i && j > i - a && j < 3 * a - i)
                    {
                        Console.Write(" *");
                    }
                    else
                    {
                        Console.Write(" ");
                    }
                }
                Console.WriteLine();
            }
        }
    }
}
